diff --git a/GenC.fu b/GenC.fu
index bb9b7cae..a3906d9a 100644
--- a/GenC.fu
+++ b/GenC.fu
@@ -2001,6 +2001,7 @@ public class GenC : GenCCpp
 			WriteEnumHasFlag(obj, args, parent);
 			break;
 		case FuId.IntTryParse:
+			Include("limits.h");
 			this.IntFunctions.Add(FuId.IntTryParse);
 			Write("FuInt");
 			WriteTryParse(obj, args);
@@ -3488,7 +3489,7 @@ public class GenC : GenCCpp
 		this.CurrentMethod = null;
 	}
 
-	void WriteIntMaxMin!(string klassName, string method, string type, int op)
+	void StartLibraryMethod!(string type, string klassName, string method, string paramType)
 	{
 		WriteNewLine();
 		Write("static ");
@@ -3498,7 +3499,12 @@ public class GenC : GenCCpp
 		WriteChar('_');
 		Write(method);
 		WriteChar('(');
-		Write(type);
+		Write(paramType);
+	}
+
+	void WriteIntMaxMin!(string klassName, string method, string type, int op)
+	{
+		StartLibraryMethod(type, klassName, method, type);
 		Write(" x, ");
 		Write(type);
 		WriteLine(" y)");
@@ -3509,21 +3515,17 @@ public class GenC : GenCCpp
 		CloseBlock();
 	}
 
-	void WriteTryParseLibrary!(string signature, string call)
+	void StartTryParseLibrary!(string klassName, string type, string baseParam)
 	{
-		WriteNewLine();
-		Write("static bool Fu");
-		WriteLine(signature);
+		StartLibraryMethod("bool", klassName, "TryParse", type);
+		Write(" *result, const char *str");
+		Write(baseParam);
+		WriteCharLine(')');
 		OpenBlock();
 		WriteLine("if (*str == '\\0')");
 		WriteLine("\treturn false;");
 		WriteLine("char *end;");
 		WriteLine("errno = 0;");
-		Write("*result = strto");
-		Write(call);
-		WriteLine(");");
-		WriteLine("return *end == '\\0' && errno == 0;");
-		CloseBlock();
 	}
 
 	void WriteIntLibrary!(string klassName, string type, SortedSet<FuId> methods)
@@ -3533,13 +3535,7 @@ public class GenC : GenCCpp
 		if (methods.Contains(FuId.MathMax))
 			WriteIntMaxMin(klassName, "Max", type, '>');
 		if (methods.Contains(FuId.MathClamp)) {
-			WriteNewLine();
-			Write("static ");
-			Write(type);
-			Write(" Fu");
-			Write(klassName);
-			Write("_Clamp(");
-			Write(type);
+			StartLibraryMethod(type, klassName, "Clamp", type);
 			Write(" x, ");
 			Write(type);
 			Write(" minValue, ");
@@ -3550,10 +3546,19 @@ public class GenC : GenCCpp
 			CloseBlock();
 		}
 		if (methods.Contains(FuId.IntTryParse)) {
-			if (klassName == "Long")
-				WriteTryParseLibrary("Long_TryParse(int64_t *result, const char *str, int base)", "ll(str, &end, base");
-			else
-				WriteTryParseLibrary("Int_TryParse(int *result, const char *str, int base)", "l(str, &end, base");
+			StartTryParseLibrary(klassName, type, ", int base");
+			if (klassName == "Int") {
+				WriteLine("long l = strtol(str, &end, base);");
+				WriteLine("if (l < INT_MIN || l > INT_MAX || *end != '\\0' || errno != 0)");
+				WriteLine("\treturn false;");
+				WriteLine("*result = (int) l;");
+				WriteLine("return true;");
+			}
+			else {
+				WriteLine("*result = strtoll(str, &end, base);");
+				WriteLine("return *end == '\\0' && errno == 0;");
+			}
+			CloseBlock();
 		}
 	}
 
@@ -3562,8 +3567,12 @@ public class GenC : GenCCpp
 		WriteIntLibrary("Int", "int", this.IntFunctions);
 		WriteIntLibrary("NInt", "ptrdiff_t", this.NIntFunctions);
 		WriteIntLibrary("Long", "int64_t", this.LongFunctions);
-		if (this.DoubleTryParse)
-			WriteTryParseLibrary("Double_TryParse(double *result, const char *str)", "d(str, &end");
+		if (this.DoubleTryParse) {
+			StartTryParseLibrary("Double", "double", "");
+			WriteLine("*result = strtod(str, &end);");
+			WriteLine("return *end == '\\0' && errno == 0;");
+			CloseBlock();
+		}
 		if (this.StringAssign) {
 			WriteNewLine();
 			WriteLine("static void FuString_Assign(char **str, char *value)");
diff --git a/libfut.cpp b/libfut.cpp
index 28afad88..d3403dc2 100644
--- a/libfut.cpp
+++ b/libfut.cpp
@@ -11437,6 +11437,7 @@ void GenC::writeCallExpr(const FuExpr * obj, const FuMethod * method, const std:
 		writeEnumHasFlag(obj, args, parent);
 		break;
 	case FuId::intTryParse:
+		include("limits.h");
 		this->intFunctions.insert(FuId::intTryParse);
 		write("FuInt");
 		writeTryParse(obj, args);
@@ -12935,7 +12936,7 @@ void GenC::writeMethod(const FuMethod * method)
 	this->currentMethod = nullptr;
 }
 
-void GenC::writeIntMaxMin(std::string_view klassName, std::string_view method, std::string_view type, int op)
+void GenC::startLibraryMethod(std::string_view type, std::string_view klassName, std::string_view method, std::string_view paramType)
 {
 	writeNewLine();
 	write("static ");
@@ -12945,7 +12946,12 @@ void GenC::writeIntMaxMin(std::string_view klassName, std::string_view method, s
 	writeChar('_');
 	write(method);
 	writeChar('(');
-	write(type);
+	write(paramType);
+}
+
+void GenC::writeIntMaxMin(std::string_view klassName, std::string_view method, std::string_view type, int op)
+{
+	startLibraryMethod(type, klassName, method, type);
 	write(" x, ");
 	write(type);
 	writeLine(" y)");
@@ -12956,21 +12962,17 @@ void GenC::writeIntMaxMin(std::string_view klassName, std::string_view method, s
 	closeBlock();
 }
 
-void GenC::writeTryParseLibrary(std::string_view signature, std::string_view call)
+void GenC::startTryParseLibrary(std::string_view klassName, std::string_view type, std::string_view baseParam)
 {
-	writeNewLine();
-	write("static bool Fu");
-	writeLine(signature);
+	startLibraryMethod("bool", klassName, "TryParse", type);
+	write(" *result, const char *str");
+	write(baseParam);
+	writeCharLine(')');
 	openBlock();
 	writeLine("if (*str == '\\0')");
 	writeLine("\treturn false;");
 	writeLine("char *end;");
 	writeLine("errno = 0;");
-	write("*result = strto");
-	write(call);
-	writeLine(");");
-	writeLine("return *end == '\\0' && errno == 0;");
-	closeBlock();
 }
 
 void GenC::writeIntLibrary(std::string_view klassName, std::string_view type, const std::set<FuId> * methods)
@@ -12980,13 +12982,7 @@ void GenC::writeIntLibrary(std::string_view klassName, std::string_view type, co
 	if (methods->contains(FuId::mathMax))
 		writeIntMaxMin(klassName, "Max", type, '>');
 	if (methods->contains(FuId::mathClamp)) {
-		writeNewLine();
-		write("static ");
-		write(type);
-		write(" Fu");
-		write(klassName);
-		write("_Clamp(");
-		write(type);
+		startLibraryMethod(type, klassName, "Clamp", type);
 		write(" x, ");
 		write(type);
 		write(" minValue, ");
@@ -12997,10 +12993,19 @@ void GenC::writeIntLibrary(std::string_view klassName, std::string_view type, co
 		closeBlock();
 	}
 	if (methods->contains(FuId::intTryParse)) {
-		if (klassName == "Long")
-			writeTryParseLibrary("Long_TryParse(int64_t *result, const char *str, int base)", "ll(str, &end, base");
-		else
-			writeTryParseLibrary("Int_TryParse(int *result, const char *str, int base)", "l(str, &end, base");
+		startTryParseLibrary(klassName, type, ", int base");
+		if (klassName == "Int") {
+			writeLine("long l = strtol(str, &end, base);");
+			writeLine("if (l < INT_MIN || l > INT_MAX || *end != '\\0' || errno != 0)");
+			writeLine("\treturn false;");
+			writeLine("*result = (int) l;");
+			writeLine("return true;");
+		}
+		else {
+			writeLine("*result = strtoll(str, &end, base);");
+			writeLine("return *end == '\\0' && errno == 0;");
+		}
+		closeBlock();
 	}
 }
 
@@ -13009,8 +13014,12 @@ void GenC::writeLibrary()
 	writeIntLibrary("Int", "int", &this->intFunctions);
 	writeIntLibrary("NInt", "ptrdiff_t", &this->nIntFunctions);
 	writeIntLibrary("Long", "int64_t", &this->longFunctions);
-	if (this->doubleTryParse)
-		writeTryParseLibrary("Double_TryParse(double *result, const char *str)", "d(str, &end");
+	if (this->doubleTryParse) {
+		startTryParseLibrary("Double", "double", "");
+		writeLine("*result = strtod(str, &end);");
+		writeLine("return *end == '\\0' && errno == 0;");
+		closeBlock();
+	}
 	if (this->stringAssign) {
 		writeNewLine();
 		writeLine("static void FuString_Assign(char **str, char *value)");
diff --git a/libfut.cs b/libfut.cs
index d1a6cb49..10eaff6d 100644
--- a/libfut.cs
+++ b/libfut.cs
@@ -11693,6 +11693,7 @@ protected override void WriteCallExpr(FuExpr obj, FuMethod method, List<FuExpr>
 				WriteEnumHasFlag(obj, args, parent);
 				break;
 			case FuId.IntTryParse:
+				Include("limits.h");
 				this.IntFunctions.Add(FuId.IntTryParse);
 				Write("FuInt");
 				WriteTryParse(obj, args);
@@ -13163,7 +13164,7 @@ protected override void WriteMethod(FuMethod method)
 			this.CurrentMethod = null;
 		}
 
-		void WriteIntMaxMin(string klassName, string method, string type, int op)
+		void StartLibraryMethod(string type, string klassName, string method, string paramType)
 		{
 			WriteNewLine();
 			Write("static ");
@@ -13173,7 +13174,12 @@ void WriteIntMaxMin(string klassName, string method, string type, int op)
 			WriteChar('_');
 			Write(method);
 			WriteChar('(');
-			Write(type);
+			Write(paramType);
+		}
+
+		void WriteIntMaxMin(string klassName, string method, string type, int op)
+		{
+			StartLibraryMethod(type, klassName, method, type);
 			Write(" x, ");
 			Write(type);
 			WriteLine(" y)");
@@ -13184,21 +13190,17 @@ void WriteIntMaxMin(string klassName, string method, string type, int op)
 			CloseBlock();
 		}
 
-		void WriteTryParseLibrary(string signature, string call)
+		void StartTryParseLibrary(string klassName, string type, string baseParam)
 		{
-			WriteNewLine();
-			Write("static bool Fu");
-			WriteLine(signature);
+			StartLibraryMethod("bool", klassName, "TryParse", type);
+			Write(" *result, const char *str");
+			Write(baseParam);
+			WriteCharLine(')');
 			OpenBlock();
 			WriteLine("if (*str == '\\0')");
 			WriteLine("\treturn false;");
 			WriteLine("char *end;");
 			WriteLine("errno = 0;");
-			Write("*result = strto");
-			Write(call);
-			WriteLine(");");
-			WriteLine("return *end == '\\0' && errno == 0;");
-			CloseBlock();
 		}
 
 		void WriteIntLibrary(string klassName, string type, SortedSet<FuId> methods)
@@ -13208,13 +13210,7 @@ void WriteIntLibrary(string klassName, string type, SortedSet<FuId> methods)
 			if (methods.Contains(FuId.MathMax))
 				WriteIntMaxMin(klassName, "Max", type, '>');
 			if (methods.Contains(FuId.MathClamp)) {
-				WriteNewLine();
-				Write("static ");
-				Write(type);
-				Write(" Fu");
-				Write(klassName);
-				Write("_Clamp(");
-				Write(type);
+				StartLibraryMethod(type, klassName, "Clamp", type);
 				Write(" x, ");
 				Write(type);
 				Write(" minValue, ");
@@ -13225,10 +13221,19 @@ void WriteIntLibrary(string klassName, string type, SortedSet<FuId> methods)
 				CloseBlock();
 			}
 			if (methods.Contains(FuId.IntTryParse)) {
-				if (klassName == "Long")
-					WriteTryParseLibrary("Long_TryParse(int64_t *result, const char *str, int base)", "ll(str, &end, base");
-				else
-					WriteTryParseLibrary("Int_TryParse(int *result, const char *str, int base)", "l(str, &end, base");
+				StartTryParseLibrary(klassName, type, ", int base");
+				if (klassName == "Int") {
+					WriteLine("long l = strtol(str, &end, base);");
+					WriteLine("if (l < INT_MIN || l > INT_MAX || *end != '\\0' || errno != 0)");
+					WriteLine("\treturn false;");
+					WriteLine("*result = (int) l;");
+					WriteLine("return true;");
+				}
+				else {
+					WriteLine("*result = strtoll(str, &end, base);");
+					WriteLine("return *end == '\\0' && errno == 0;");
+				}
+				CloseBlock();
 			}
 		}
 
@@ -13237,8 +13242,12 @@ void WriteLibrary()
 			WriteIntLibrary("Int", "int", this.IntFunctions);
 			WriteIntLibrary("NInt", "ptrdiff_t", this.NIntFunctions);
 			WriteIntLibrary("Long", "int64_t", this.LongFunctions);
-			if (this.DoubleTryParse)
-				WriteTryParseLibrary("Double_TryParse(double *result, const char *str)", "d(str, &end");
+			if (this.DoubleTryParse) {
+				StartTryParseLibrary("Double", "double", "");
+				WriteLine("*result = strtod(str, &end);");
+				WriteLine("return *end == '\\0' && errno == 0;");
+				CloseBlock();
+			}
 			if (this.StringAssign) {
 				WriteNewLine();
 				WriteLine("static void FuString_Assign(char **str, char *value)");
diff --git a/libfut.hpp b/libfut.hpp
index 04238319..6f1b7baa 100644
--- a/libfut.hpp
+++ b/libfut.hpp
@@ -2336,8 +2336,9 @@ class GenC : public GenCCpp
 	void writeDestructFields(const FuSymbol * symbol);
 	void writeNewDelete(const FuClass * klass, bool define);
 	static bool canThrow(const FuType * type);
+	void startLibraryMethod(std::string_view type, std::string_view klassName, std::string_view method, std::string_view paramType);
 	void writeIntMaxMin(std::string_view klassName, std::string_view method, std::string_view type, int op);
-	void writeTryParseLibrary(std::string_view signature, std::string_view call);
+	void startTryParseLibrary(std::string_view klassName, std::string_view type, std::string_view baseParam);
 	void writeIntLibrary(std::string_view klassName, std::string_view type, const std::set<FuId> * methods);
 	void writeLibrary();
 };
diff --git a/libfut.js b/libfut.js
index 072a3725..a35ef6bf 100644
--- a/libfut.js
+++ b/libfut.js
@@ -12148,6 +12148,7 @@ export class GenC extends GenCCpp
 			this.writeEnumHasFlag(obj, args, parent);
 			break;
 		case FuId.INT_TRY_PARSE:
+			this.include("limits.h");
 			this.#intFunctions.add(FuId.INT_TRY_PARSE);
 			this.write("FuInt");
 			this.#writeTryParse(obj, args);
@@ -13640,7 +13641,7 @@ export class GenC extends GenCCpp
 		this.currentMethod = null;
 	}
 
-	#writeIntMaxMin(klassName, method, type, op)
+	#startLibraryMethod(type, klassName, method, paramType)
 	{
 		this.writeNewLine();
 		this.write("static ");
@@ -13650,7 +13651,12 @@ export class GenC extends GenCCpp
 		this.writeChar(95);
 		this.write(method);
 		this.writeChar(40);
-		this.write(type);
+		this.write(paramType);
+	}
+
+	#writeIntMaxMin(klassName, method, type, op)
+	{
+		this.#startLibraryMethod(type, klassName, method, type);
 		this.write(" x, ");
 		this.write(type);
 		this.writeLine(" y)");
@@ -13661,21 +13667,17 @@ export class GenC extends GenCCpp
 		this.closeBlock();
 	}
 
-	#writeTryParseLibrary(signature, call)
+	#startTryParseLibrary(klassName, type, baseParam)
 	{
-		this.writeNewLine();
-		this.write("static bool Fu");
-		this.writeLine(signature);
+		this.#startLibraryMethod("bool", klassName, "TryParse", type);
+		this.write(" *result, const char *str");
+		this.write(baseParam);
+		this.writeCharLine(41);
 		this.openBlock();
 		this.writeLine("if (*str == '\\0')");
 		this.writeLine("\treturn false;");
 		this.writeLine("char *end;");
 		this.writeLine("errno = 0;");
-		this.write("*result = strto");
-		this.write(call);
-		this.writeLine(");");
-		this.writeLine("return *end == '\\0' && errno == 0;");
-		this.closeBlock();
 	}
 
 	#writeIntLibrary(klassName, type, methods)
@@ -13685,13 +13687,7 @@ export class GenC extends GenCCpp
 		if (methods.has(FuId.MATH_MAX))
 			this.#writeIntMaxMin(klassName, "Max", type, 62);
 		if (methods.has(FuId.MATH_CLAMP)) {
-			this.writeNewLine();
-			this.write("static ");
-			this.write(type);
-			this.write(" Fu");
-			this.write(klassName);
-			this.write("_Clamp(");
-			this.write(type);
+			this.#startLibraryMethod(type, klassName, "Clamp", type);
 			this.write(" x, ");
 			this.write(type);
 			this.write(" minValue, ");
@@ -13702,10 +13698,19 @@ export class GenC extends GenCCpp
 			this.closeBlock();
 		}
 		if (methods.has(FuId.INT_TRY_PARSE)) {
-			if (klassName == "Long")
-				this.#writeTryParseLibrary("Long_TryParse(int64_t *result, const char *str, int base)", "ll(str, &end, base");
-			else
-				this.#writeTryParseLibrary("Int_TryParse(int *result, const char *str, int base)", "l(str, &end, base");
+			this.#startTryParseLibrary(klassName, type, ", int base");
+			if (klassName == "Int") {
+				this.writeLine("long l = strtol(str, &end, base);");
+				this.writeLine("if (l < INT_MIN || l > INT_MAX || *end != '\\0' || errno != 0)");
+				this.writeLine("\treturn false;");
+				this.writeLine("*result = (int) l;");
+				this.writeLine("return true;");
+			}
+			else {
+				this.writeLine("*result = strtoll(str, &end, base);");
+				this.writeLine("return *end == '\\0' && errno == 0;");
+			}
+			this.closeBlock();
 		}
 	}
 
@@ -13714,8 +13719,12 @@ export class GenC extends GenCCpp
 		this.#writeIntLibrary("Int", "int", this.#intFunctions);
 		this.#writeIntLibrary("NInt", "ptrdiff_t", this.#nIntFunctions);
 		this.#writeIntLibrary("Long", "int64_t", this.#longFunctions);
-		if (this.#doubleTryParse)
-			this.#writeTryParseLibrary("Double_TryParse(double *result, const char *str)", "d(str, &end");
+		if (this.#doubleTryParse) {
+			this.#startTryParseLibrary("Double", "double", "");
+			this.writeLine("*result = strtod(str, &end);");
+			this.writeLine("return *end == '\\0' && errno == 0;");
+			this.closeBlock();
+		}
 		if (this.#stringAssign) {
 			this.writeNewLine();
 			this.writeLine("static void FuString_Assign(char **str, char *value)");