diff --git a/embedded_cli.c b/embedded_cli.c
index a594a39..adcd1b5 100644
--- a/embedded_cli.c
+++ b/embedded_cli.c
@@ -4,7 +4,6 @@
  *    https://en.wikipedia.org/wiki/ANSI_escape_code
  */
 
-#include <stdio.h>
 #include <string.h>
 
 #include "embedded_cli.h"
diff --git a/embedded_cli.h b/embedded_cli.h
index c2bc5f6..49c33f9 100644
--- a/embedded_cli.h
+++ b/embedded_cli.h
@@ -2,6 +2,7 @@
 #define EMBEDDED_CLI
 
 #include <stdbool.h>
+#include <stddef.h>
 
 #ifndef EMBEDDED_CLI_MAX_LINE
 /**
diff --git a/examples/posix_demo.c b/examples/posix_demo.c
index e500faf..57cc9a8 100644
--- a/examples/posix_demo.c
+++ b/examples/posix_demo.c
@@ -95,7 +95,7 @@ int main(void)
             cli_argc = embedded_cli_argc(&cli, &cli_argv);
             printf("Got %d args\n", cli_argc);
             for (int i = 0; i < cli_argc; i++) {
-                printf("Arg %d/%d: [%lu bytes] '%s'\n", i, cli_argc,
+                printf("Arg %d/%d: [%zu bytes] '%s'\n", i, cli_argc,
                        strlen(cli_argv[i]), cli_argv[i]);
             }
             done = cli_argc >= 1 && (strcmp(cli_argv[0], "quit") == 0);
diff --git a/tests/sizes.sh b/tests/sizes.sh
new file mode 100755
index 0000000..3edceb6
--- /dev/null
+++ b/tests/sizes.sh
@@ -0,0 +1,63 @@
+#!/bin/bash
+
+# Configuration
+CC=arm-none-eabi-gcc
+SIZE=arm-none-eabi-size
+NM=arm-none-eabi-nm
+
+# Use -ffreestanding and provide minimal headers to avoid toolchain dependencies
+CFLAGS="-mthumb -mcpu=cortex-m3 -Os -I. -std=c99 -ffreestanding"
+
+# Create a mock include directory
+mkdir -p mock_incl
+
+cat <<EOF > mock_incl/string.h
+#include <stddef.h>
+void *memset(void *s, int c, size_t n);
+char *strncpy(char *dest, const char *src, size_t n);
+size_t strlen(const char *s);
+int strcmp(const char *s1, const char *s2);
+void *memcpy(void *dest, const void *src, size_t n);
+void *memmove(void *dest, const void *src, size_t n);
+char *strstr(const char *haystack, const char *needle);
+EOF
+
+# Compile embedded_cli.c to object file
+$CC $CFLAGS -Imock_incl -c embedded_cli.c -o embedded_cli.o
+
+if [ $? -ne 0 ]; then
+    echo "Error: Compilation of embedded_cli.c failed"
+    rm -rf mock_incl
+    exit 1
+fi
+
+echo "Binary sizes (ARM Thumb-2, -Os):"
+$SIZE embedded_cli.o
+
+# Calculate size of the structure
+cat <<EOF > struct_size.c
+#include "embedded_cli.h"
+struct embedded_cli cli;
+EOF
+
+$CC $CFLAGS -Imock_incl -c struct_size.c -o struct_size.o
+if [ $? -ne 0 ]; then
+    echo "Error: Compilation of struct_size.c failed"
+    rm -rf mock_incl embedded_cli.o struct_size.c
+    exit 1
+fi
+
+# Get size using nm
+STRUCT_SIZE_HEX=$($NM -S struct_size.o | grep " cli" | awk '{print $2}')
+
+if [ -z "$STRUCT_SIZE_HEX" ]; then
+    echo "Error: Could not find 'cli' symbol in object file"
+else
+    # Convert hex size from nm to decimal
+    STRUCT_SIZE_DECIMAL=$((16#$STRUCT_SIZE_HEX))
+    echo ""
+    echo "Size of struct embedded_cli: $STRUCT_SIZE_DECIMAL bytes"
+fi
+
+# Cleanup
+rm -rf embedded_cli.o struct_size.c struct_size.o mock_incl