diff --git a/src/cmd.cpp b/src/cmd.cpp
index 1823b8d..de49aa0 100644
--- a/src/cmd.cpp
+++ b/src/cmd.cpp
@@ -244,7 +244,7 @@ static constexpr size_t strlen_pre_eq(const char* str){
 #define CHECK_VALID_SHORT_ARG(opt, arg, type) \
 	{ \
 		if(next_arg == argc || !is_##type(arg)){ \
-			fprintf(stderr, "'-%s' requires an argument of type " #type "\n", opt); \
+			fprintf(stderr, "'-%c' requires an argument of type " #type "\n", opt); \
 			ret.error = 1; \
 			break; \
 		} \
@@ -389,15 +389,15 @@ cmd_args process_cmd_args(int argc, char** argv){
 			}else if(CHECK_LONG_OPTION(INVERT, arg)){
 				ret.invert = 1;
 			}else if(CHECK_LONG_OPTION_WITH_ARG(SEED, arg)){
-				constexpr size_t offset = strlen_pre_eq(SEED_LONG_OPTION);
+				constexpr int offset = strlen_pre_eq(SEED_LONG_OPTION);
 				CHECK_VALID_LONG_INT_ARG(SEED, offset, arg);
 				ret.seed = atol(arg+offset+1);
 			}else if(CHECK_LONG_OPTION_WITH_ARG(SPREAD, arg)){
-				constexpr size_t offset = strlen_pre_eq(SPREAD_LONG_OPTION);
+				constexpr int offset = strlen_pre_eq(SPREAD_LONG_OPTION);
 				CHECK_VALID_LONG_FLOAT_ARG(SPREAD, offset, arg);
 				ret.spread = atof(arg+offset+1);
 			}else if(CHECK_LONG_OPTION_WITH_ARG(FREQ, arg)){
-				constexpr size_t offset = strlen_pre_eq(FREQ_LONG_OPTION);
+				constexpr int offset = strlen_pre_eq(FREQ_LONG_OPTION);
 				CHECK_VALID_LONG_FLOAT_ARG(FREQ, offset, arg);
 				ret.freq = atof(arg+offset+1);
 			}else if(CHECK_LONG_OPTION(IGNORE_ANIMATE, arg)  ||