diff --git a/tests/suites/test_suite_base64.function b/tests/suites/test_suite_base64.function
index 27b6c13..b8ddba7 100644
--- a/tests/suites/test_suite_base64.function
+++ b/tests/suites/test_suite_base64.function
@@ -18,7 +18,7 @@
     memset(src_str, 0x00, 1000);
     memset(dst_str, 0x00, 1000);
 
-    strcpy( (char *) src_str, src_string );
+    strncpy( (char *) src_str, src_string, sizeof(src_str) - 1 );
     TEST_ASSERT( base64_encode( dst_str, &len, src_str, strlen( (char *) src_str ) ) == result );
     if( result == 0 )
     {
@@ -37,8 +37,8 @@
 
     memset(src_str, 0x00, 1000);
     memset(dst_str, 0x00, 1000);
-    
-    strcpy( (char *) src_str, src_string );
+
+    strncpy( (char *) src_str, src_string, sizeof(src_str) - 1 );
     TEST_ASSERT( res = base64_decode( dst_str, &len, src_str, strlen( (char *) src_str ) ) == result );
     if( result == 0 )
     {
diff --git a/tests/suites/test_suite_md.function b/tests/suites/test_suite_md.function
index 4b5921f..7b6f9e5 100644
--- a/tests/suites/test_suite_md.function
+++ b/tests/suites/test_suite_md.function
@@ -70,9 +70,8 @@
     memset(hash_str, 0x00, 1000);
     memset(output, 0x00, 100);
 
-    strcpy( (char *) src_str, text_src_string );
-    
-    strncpy( (char *) md_name, text_md_name, 100 );
+    strncpy( (char *) src_str, text_src_string, sizeof(src_str) - 1 );
+    strncpy( (char *) md_name, text_md_name, sizeof(md_name) - 1 );
     md_info = md_info_from_string(md_name);
     TEST_ASSERT( md_info != NULL );
 
@@ -98,7 +97,7 @@
     memset(hash_str, 0x00, 10000);
     memset(output, 0x00, 100);
 
-    strncpy( (char *) md_name, text_md_name, 100 );
+    strncpy( (char *) md_name, text_md_name, sizeof(md_name) - 1 );
     md_info = md_info_from_string(md_name);
     TEST_ASSERT( md_info != NULL );
 
@@ -128,9 +127,8 @@
     memset(hash_str, 0x00, 1000);
     memset(output, 0x00, 100);
 
-    strcpy( (char *) src_str, text_src_string );
-    
-    strncpy( (char *) md_name, text_md_name, 100 );
+    strncpy( (char *) src_str, text_src_string, sizeof(src_str) - 1 );
+    strncpy( (char *) md_name, text_md_name, sizeof(md_name) - 1 );
     md_info = md_info_from_string(md_name);
     TEST_ASSERT( md_info != NULL );
     TEST_ASSERT ( 0 == md_init_ctx( &ctx, md_info ) );
@@ -164,7 +162,7 @@
     memset(hash_str, 0x00, 10000);
     memset(output, 0x00, 100);
 
-    strncpy( (char *) md_name, text_md_name, 100 );
+    strncpy( (char *) md_name, text_md_name, sizeof(md_name) - 1 );
     md_info = md_info_from_string(md_name);
     TEST_ASSERT( md_info != NULL );
     TEST_ASSERT ( 0 == md_init_ctx( &ctx, md_info ) );
@@ -201,7 +199,7 @@
     memset(hash_str, 0x00, 10000);
     memset(output, 0x00, 100);
 
-    strncpy( (char *) md_name, text_md_name, 100 );
+    strncpy( (char *) md_name, text_md_name, sizeof(md_name) - 1 );
     md_info = md_info_from_string( md_name );
     TEST_ASSERT( md_info != NULL );
 
@@ -234,7 +232,7 @@
     memset(hash_str, 0x00, 10000);
     memset(output, 0x00, 100);
 
-    strncpy( (char *) md_name, text_md_name, 100 );
+    strncpy( (char *) md_name, text_md_name, sizeof(md_name) - 1 );
     md_info = md_info_from_string( md_name );
     TEST_ASSERT( md_info != NULL );
     TEST_ASSERT ( 0 == md_init_ctx( &ctx, md_info ) );
@@ -278,7 +276,7 @@
     memset(hash_str, 0x00, 1000);
     memset(output, 0x00, 100);
 
-    strncpy( (char *) md_name, text_md_name, 100 );
+    strncpy( (char *) md_name, text_md_name, sizeof(md_name) - 1 );
     md_info = md_info_from_string( md_name );
     TEST_ASSERT( md_info != NULL );
 
diff --git a/tests/suites/test_suite_mdx.function b/tests/suites/test_suite_mdx.function
index 0676d82..24fb328 100644
--- a/tests/suites/test_suite_mdx.function
+++ b/tests/suites/test_suite_mdx.function
@@ -16,7 +16,7 @@
     memset( hash_str, 0x00, sizeof hash_str );
     memset( output, 0x00, sizeof output );
 
-    strcpy( (char *) src_str, text_src_string );
+    strncpy( (char *) src_str, text_src_string, sizeof(src_str) - 1 );
 
     md2( src_str, strlen( (char *) src_str ), output );
     hexify( hash_str, output, sizeof  output );
@@ -36,7 +36,7 @@
     memset( hash_str, 0x00, sizeof hash_str );
     memset( output, 0x00, sizeof output );
 
-    strcpy( (char *) src_str, text_src_string );
+    strncpy( (char *) src_str, text_src_string, sizeof(src_str) - 1 );
 
     md4( src_str, strlen( (char *) src_str ), output );
     hexify( hash_str, output, sizeof  output );
@@ -56,7 +56,7 @@
     memset( hash_str, 0x00, sizeof hash_str );
     memset( output, 0x00, sizeof output );
 
-    strcpy( (char *) src_str, text_src_string );
+    strncpy( (char *) src_str, text_src_string, sizeof(src_str) - 1 );
 
     md5( src_str, strlen( (char *) src_str ), output );
     hexify( hash_str, output, sizeof  output );
@@ -76,7 +76,7 @@
     memset(hash_str, 0x00, sizeof hash_str);
     memset(output, 0x00, sizeof output);
 
-    strcpy( (char *) src_str, text_src_string );
+    strncpy( (char *) src_str, text_src_string, sizeof(src_str) - 1 );
 
     ripemd160( src_str, strlen( (char *) src_str ), output );
     hexify( hash_str, output, sizeof output );