diff --git a/src/config.h.in b/src/config.h.in
new file mode 100644
index 0000000000..845de4cde4
--- /dev/null
+++ b/src/config.h.in
@@ -0,0 +1,3 @@
+#pragma once
+#mesondefine ENT_GETENTROPY
+#mesondefine ENT_GE_SYSRANDOM
diff --git a/src/meson.build b/src/meson.build
index 04fe34f782..8dd73b6804 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -46,8 +46,11 @@ if not have_getentropy
 endif
 
 
-config_file = configure_file(output: 'config.h',
-                             configuration: conf_data)
+config_file = configure_file(
+  output: 'config.h',
+  input: 'config.h.in',
+  configuration: conf_data,
+)
 
 ent_sources = ['ent.c', config_file]