diff --git a/IO/Image/vtkNIFTIImageReader.cxx b/IO/Image/vtkNIFTIImageReader.cxx
index 52e569e2c99f789a93e826fdd8ebf61c65521ba8..e1a69785302818fc42564dc9b1d2aca8631b31fb 100644
--- a/IO/Image/vtkNIFTIImageReader.cxx
+++ b/IO/Image/vtkNIFTIImageReader.cxx
@@ -115,7 +115,7 @@ void vtkNIFTIImageReaderSwapHeader(nifti_1_header* hdr)
   vtkByteSwap::SwapVoidRange(&hdr->glmin, 1, 4);
 
   // All NIFTI-specific (meaning is totally different in Analyze 7.5)
-  if (strncmp(hdr->magic, "ni1", 4) == 0 || strncmp(hdr->magic, "n+1", 4) == 0)
+  if (strncmp(hdr->magic, "ni1", 3) == 0 || strncmp(hdr->magic, "n+1", 3) == 0)
   {
     vtkByteSwap::SwapVoidRange(&hdr->qform_code, 1, 2);
     vtkByteSwap::SwapVoidRange(&hdr->sform_code, 1, 2);
diff --git a/IO/Legacy/vtkDataReader.cxx b/IO/Legacy/vtkDataReader.cxx
index a0c54769516585b7db5a3aaf2a3fcbcc1f2112b4..4893fd0a31ac87c32cebe4aa68eea84c26c2e8fe 100644
--- a/IO/Legacy/vtkDataReader.cxx
+++ b/IO/Legacy/vtkDataReader.cxx
@@ -1145,7 +1145,7 @@ int vtkDataReader::ReadVertexData(vtkGraph* g, vtkIdType numVertices)
     //
     // maybe bumped into edge data
     //
-    else if (!strncmp(line, "edge_data", 10))
+    else if (!strncmp(line, "edge_data", 9))
     {
       vtkIdType npts;
       if (!this->Read(&npts))