diff --git a/README b/README
index 87cd3b5..1cc027f 100644
--- a/README
+++ b/README
@@ -70,6 +70,10 @@ OPTIONS
   -v                 increase verbosity level
   -h, --help         display this help and exit
 
+Environment variables:
+
+EVMCTL_KEY_PASSWORD  : Private key password to use; do not use --pass option
+
 
 INTRODUCTION
 ------------
diff --git a/src/evmctl.c b/src/evmctl.c
index 5f7c2b8..9d661d7 100644
--- a/src/evmctl.c
+++ b/src/evmctl.c
@@ -2534,6 +2534,9 @@ static void usage(void)
 		"      --ignore-violations ignore ToMToU measurement violations\n"
 		"  -v                 increase verbosity level\n"
 		"  -h, --help         display this help and exit\n"
+		"\n"
+		"Environment variables:\n\n"
+		"EVMCTL_KEY_PASSWORD  : Private key password to use; do not use --pass option\n"
 		"\n");
 }
 
@@ -2822,6 +2825,9 @@ int main(int argc, char *argv[])
 		}
 	}
 
+	if (!imaevm_params.keypass)
+		imaevm_params.keypass = getenv("EVMCTL_KEY_PASSWORD");
+
 	if (argv[optind] == NULL)
 		usage();
 	else