diff --git a/flatpak-dev-shim/jni/Makefile b/flatpak-dev-shim/jni/Makefile
index bd82a2f..4162930 100644
--- a/flatpak-dev-shim/jni/Makefile
+++ b/flatpak-dev-shim/jni/Makefile
@@ -10,7 +10,7 @@
 OBJECTS=FlatpakProcessImpl.o
 LIBRARY=$(OUT_DIR)/libflatpakdevshim.so
 
-CFLAGS += -fPIC -D_REENTRANT -I$(JAVA_HOME)/include -I$(JAVA_HOME)/include/linux
+CFLAGS += -fPIC -D_REENTRANT -I$(JAVA_HOME)/include -I$(JAVA_HOME)/include/linux -std=c99
 
 java_lang_FlatpakProcessImpl.h:
 	$(JAVA_HOME)/bin/javac -h . -d $(OUT_DIR)/native --patch-module=java.base=../src/main/java ../src/main/java/java/lang/FlatpakProcessImpl.java