diff --git a/src/3rdparty/modp_numtoa.c b/src/3rdparty/modp_numtoa.c
index 2224ad2d47..be9cf736c4 100644
--- a/src/3rdparty/modp_numtoa.c
+++ b/src/3rdparty/modp_numtoa.c
@@ -116,7 +116,7 @@ size_t modp_itoa10(int32_t value, char* str)
 
     // Reverse string
     strreverse(str,wstr-1);
-    return wstr - str - 1;
+    return wstr - str;
 }
 
 size_t modp_uitoa10(uint32_t value, char* str)
@@ -127,7 +127,7 @@ size_t modp_uitoa10(uint32_t value, char* str)
     *wstr='\0';
     // Reverse string
     strreverse(str, wstr-1);
-    return wstr - str - 1;
+    return wstr - str;
 }
 
 size_t modp_litoa10(int64_t value, char* str)
@@ -142,7 +142,7 @@ size_t modp_litoa10(int64_t value, char* str)
 
     // Reverse string
     strreverse(str,wstr-1);
-    return wstr - str - 1;
+    return wstr - str;
 }
 
 size_t modp_ulitoa10(uint64_t value, char* str)
@@ -153,7 +153,7 @@ size_t modp_ulitoa10(uint64_t value, char* str)
     *wstr='\0';
     // Reverse string
     strreverse(str, wstr-1);
-    return wstr - str - 1;
+    return wstr - str;
 }
 
 size_t modp_dtoa(double value, char* str, int prec)
@@ -251,7 +251,7 @@ size_t modp_dtoa(double value, char* str, int prec)
     }
     *wstr='\0';
     strreverse(str, wstr-1);
-    return wstr - str - 1;
+    return wstr - str;
 }
 
 
@@ -372,7 +372,7 @@ size_t modp_dtoa2(double value, char* str, int prec)
     }
     *wstr='\0';
     strreverse(str, wstr-1);
-    return wstr - str - 1;
+    return wstr - str;
 }
 
 // This is near identical to modp_dtoa2 above, excep that it never uses
@@ -502,5 +502,5 @@ size_t modp_dtoa3(double value, char* str, int n, int prec)
     }
     *wstr='\0';
     strreverse(str, wstr-1);
-    return wstr - str - 1;
+    return wstr - str;
 }