diff --git a/src/osgPlugins/stl/ReaderWriterSTL.cpp b/src/osgPlugins/stl/ReaderWriterSTL.cpp
index b9697f1de..9e23d1b00 100644
--- a/src/osgPlugins/stl/ReaderWriterSTL.cpp
+++ b/src/osgPlugins/stl/ReaderWriterSTL.cpp
@@ -400,12 +400,12 @@ const float StlColorDepth = float(StlColorSize); // 2^5 - 1
 // Magics files have a header with a "COLOR=" field giving the color of the whole model
 bool fileComesFromMagics(FILE *fp, osg::Vec4& magicsColor)
 {
-    char header[80];
+    std::string header(80, 0);
     const float magicsColorDepth = 255.f;
 
     ::rewind(fp);
 
-    if (fread((void*) &header, sizeof(header), 1, fp) != 1)
+    if (fread((void*) &(*header.begin()), header.size(), 1, fp) != 1)
         return false;
 
     if (::fseek(fp, sizeof_StlHeader, SEEK_SET)!=0)
@@ -414,8 +414,7 @@ bool fileComesFromMagics(FILE *fp, osg::Vec4& magicsColor)
     }
 
     std::string magicsColorPattern ("COLOR=");
-    std::string headerStr = std::string(header);
-    if(size_t colorFieldPos = headerStr.find(magicsColorPattern) != std::string::npos)
+    if(size_t colorFieldPos = header.find(magicsColorPattern) != std::string::npos)
     {
         int colorIndex = colorFieldPos + magicsColorPattern.size() - 1;
         float r = (uint8_t)header[colorIndex] / magicsColorDepth;