diff --git a/renderdoc/core/core.cpp b/renderdoc/core/core.cpp
index b05fd3ed0..52111c6b7 100644
--- a/renderdoc/core/core.cpp
+++ b/renderdoc/core/core.cpp
@@ -43,7 +43,7 @@ bool is_exr_file(FILE *f)
   const uint32_t openexr_magic = MAKE_FOURCC(0x76, 0x2f, 0x31, 0x01);
 
   uint32_t magic = 0;
-  size_t bytesRead = FileIO::fread(&magic, sizeof(magic), 1, f);
+  size_t bytesRead = FileIO::fread(&magic, 1, sizeof(magic), f);
 
   FileIO::fseek64(f, 0, SEEK_SET);