diff --git a/src/OpenColorIO/ParseUtils.cpp b/src/OpenColorIO/ParseUtils.cpp
index 31667abbec..eaeefc00e4 100644
--- a/src/OpenColorIO/ParseUtils.cpp
+++ b/src/OpenColorIO/ParseUtils.cpp
@@ -610,7 +610,7 @@ bool StringVecToFloatVec(std::vector<float> &floatArray, const StringUtils::Stri
     {
         float x = NAN;
         const char *str = lineParts[i].c_str();
-        const auto result = NumberUtils::from_chars(str, str + strlen(str), x);
+        const auto result = NumberUtils::from_chars(str, str + lineParts[i].size(), x);
         if (result.ec != std::errc())
         {
             return false;
diff --git a/src/OpenColorIO/fileformats/FileFormatSpi1D.cpp b/src/OpenColorIO/fileformats/FileFormatSpi1D.cpp
index dbec3963e9..45ca9dce06 100755
--- a/src/OpenColorIO/fileformats/FileFormatSpi1D.cpp
+++ b/src/OpenColorIO/fileformats/FileFormatSpi1D.cpp
@@ -238,7 +238,7 @@ CachedFileRcPtr LocalFileFormat::read(std::istream & istream,
                 for (int i = 0; i < components; i++)
                 {
                     float v = NAN;
-                    const auto result = NumberUtils::from_chars(inputLUT[i], inputLUT[i] + strlen(inputLUT[i]), v);
+                    const auto result = NumberUtils::from_chars(inputLUT[i], inputLUT[i] + 64, v);
 
                     if (result.ec != std::errc())
                     {