diff --git a/Makefile b/Makefile
index 584c692..c30a732 100644
--- a/Makefile
+++ b/Makefile
@@ -6,7 +6,7 @@ SRC := src
 CC ?= gcc
 AR ?= ar
 CFLAGS ?= -O2 -Wall -Wextra
-CFLAGS := ${CFLAGS} -I.
+CFLAGS := ${CFLAGS} -I. -D_IN_MINITAR
 DESTDIR ?= /usr/local
 
 OBJS := $(OBJ)/tar.o \
diff --git a/minitar.h b/minitar.h
index be63f29..a99b3f4 100644
--- a/minitar.h
+++ b/minitar.h
@@ -3,10 +3,14 @@
 #include <stdio.h>
 #include <sys/types.h>
 
+#ifdef _IN_MINITAR
 struct minitar
 {
     FILE* stream;
 };
+#else
+struct minitar;
+#endif
 
 enum minitar_file_type
 {