diff --git a/nanosvg/nanosvg.h b/nanosvg/nanosvg.h
index 2321c56fd..bd5b722f4 100644
--- a/nanosvg/nanosvg.h
+++ b/nanosvg/nanosvg.h
@@ -1081,7 +1081,7 @@ static double nsvg__atof(const char* s)
 	char* cur = (char*)s;
 	char* end = NULL;
 	double res = 0.0, sign = 1.0;
-	long long intPart = 0, fracPart = 0;
+	double intPart = 0, fracPart = 0;
 	char hasIntPart = 0, hasFracPart = 0;
 
 	// Parse optional sign
@@ -1095,7 +1095,11 @@ static double nsvg__atof(const char* s)
 	// Parse integer part
 	if (nsvg__isdigit(*cur)) {
 		// Parse digit sequence
-		intPart = (double)strtoll(cur, &end, 10);
+#ifdef _MSC_VER
+          intPart = (double)_strtoi64(cur, &end, 10);
+#else
+          intPart = (double)strtoll(cur, &end, 10);
+#endif
 		if (cur != end) {
 			res = (double)intPart;
 			hasIntPart = 1;
@@ -1108,7 +1112,11 @@ static double nsvg__atof(const char* s)
 		cur++; // Skip '.'
 		if (nsvg__isdigit(*cur)) {
 			// Parse digit sequence
-			fracPart = strtoll(cur, &end, 10);
+#ifdef _MSC_VER
+                        fracPart = (double)_strtoi64(cur, &end, 10);
+#else
+                        fracPart = (double)strtoll(cur, &end, 10);
+#endif
 			if (cur != end) {
 				res += (double)fracPart / pow(10.0, (double)(end - cur));
 				hasFracPart = 1;
@@ -1123,11 +1131,11 @@ static double nsvg__atof(const char* s)
 
 	// Parse optional exponent
 	if (*cur == 'e' || *cur == 'E') {
-		int expPart = 0;
+		double expPart = 0;
 		cur++; // skip 'E'
-		expPart = strtol(cur, &end, 10); // Parse digit sequence with sign
+		expPart = (double)strtol(cur, &end, 10); // Parse digit sequence with sign
 		if (cur != end) {
-			res *= pow(10.0, (double)expPart);
+			res *= pow(10.0, expPart);
 		}
 	}
 
diff --git a/src/Fl_SVG_Image.cxx b/src/Fl_SVG_Image.cxx
index 04a4d455e..91be0c70d 100644
--- a/src/Fl_SVG_Image.cxx
+++ b/src/Fl_SVG_Image.cxx
@@ -25,17 +25,15 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-#ifdef HAVE_LONG_LONG
-  typedef long long fl_nsvg_int;
-#else
-  typedef long fl_nsvg_int;
-# define strtoll(a, b, c) strtol(a, b, c)
+#if !defined(HAVE_LONG_LONG)
+static double strtoll(const char *str, char **endptr, int base) {
+  return (double)strtol(str, endptr, base);
+}
 #endif
 
-
 #define NANOSVG_ALL_COLOR_KEYWORDS	// Include full list of color keywords.
 #define NANOSVG_IMPLEMENTATION		// Expands implementation
-#include "../nanosvg/fl_nanosvg.h"
+#include "../nanosvg/nanosvg.h"
 
 #define NANOSVGRAST_IMPLEMENTATION	// Expands implementation
 #include "../nanosvg/altsvgrast.h"