diff --git a/src/zm_image.cpp b/src/zm_image.cpp
index 0464e6c25..6a301f165 100644
--- a/src/zm_image.cpp
+++ b/src/zm_image.cpp
@@ -633,7 +633,7 @@ bool Image::WriteRaw( const char *filename ) const
 
 bool Image::ReadJpeg( const char *filename, int p_colours, int p_subpixelorder)
 {
-	unsigned int new_width, new_height, new_colours, new_subpixelorder;
+	int new_width, new_height, new_colours, new_subpixelorder;
 	struct jpeg_decompress_struct *cinfo = jpg_dcinfo;
 
 	if ( !cinfo )
@@ -886,7 +886,7 @@ bool Image::WriteJpeg( const char *filename, int quality_override ) const
 
 bool Image::DecodeJpeg( const JOCTET *inbuffer, int inbuffer_size, int p_colours, int p_subpixelorder)
 {
-	unsigned int new_width, new_height, new_colours, new_subpixelorder;
+	int new_width, new_height, new_colours, new_subpixelorder;
 	struct jpeg_decompress_struct *cinfo = jpg_dcinfo;
 
 	if ( !cinfo )
diff --git a/src/zm_monitor.cpp b/src/zm_monitor.cpp
index 463cf2b07..79d96e234 100644
--- a/src/zm_monitor.cpp
+++ b/src/zm_monitor.cpp
@@ -2727,7 +2727,7 @@ int Monitor::Capture()
     }
     if ( true ) {
 
-        if ( capture_image->Size() != camera->ImageSize() )
+        if ( capture_image->Size() != (int)camera->ImageSize() )
         {
             Error( "Captured image does not match expected size, check width, height and colour depth" );
             return( -1 );
diff --git a/src/zmf.cpp b/src/zmf.cpp
index 60c00967e..b37285122 100644
--- a/src/zmf.cpp
+++ b/src/zmf.cpp
@@ -240,14 +240,14 @@ int main( int argc, char *argv[] )
 		{
                         n_bytes = read( sd, image_data+bytes_read, frame_header.image_length-bytes_read );
                         if (n_bytes < 0) break; // break on error
-                        if (n_bytes < frame_header.image_length)
+                        if (n_bytes < (int)frame_header.image_length)
 			{
                                 // print some informational messages 
                                 if (bytes_read == 0)
                                 {
                                         // Warning("Image read : Short read %d bytes of %d expected bytes",n_bytes,frame_header.image_length);
                                 }
-                                else if (bytes_read+n_bytes == frame_header.image_length)
+                                else if (bytes_read+n_bytes == (int)frame_header.image_length)
                                 {
                                         // Warning("Image read : Read rest of short read: %d bytes read total of %d bytes",n_bytes,frame_header.image_length);
                                 }