diff --git a/Makefile b/Makefile
index a7cee65cf..85e3b1177 100644
--- a/Makefile
+++ b/Makefile
@@ -1,10 +1,10 @@
 # Set the compiler, if it's not set by the environment.
 ifndef GXX
-	GXX = g++-9
+	GXX = g++-10
 endif
 
 ifndef CC
-	CC = gcc-9
+	CC = gcc-10
 endif
 
 GIT_REVISION = $(shell git rev-parse --short HEAD)
diff --git a/libstuff/libstuff.cpp b/libstuff/libstuff.cpp
index 2b974144b..2f43821b5 100644
--- a/libstuff/libstuff.cpp
+++ b/libstuff/libstuff.cpp
@@ -26,7 +26,7 @@
 #endif
 
 // Common error definitions
-#define S_errno errno
+#define S_errno (unsigned int) errno
 #define S_NOTINITIALISED 0xFEFEFEFE // Doesn't exist for Linux
 #ifdef __APPLE__
 // The above doesn't even build on OS X with C++11 turned on. I don't know why