diff --git a/src/jtag/adapter.c b/src/jtag/adapter.c
index 14452d42f..519505dc3 100644
--- a/src/jtag/adapter.c
+++ b/src/jtag/adapter.c
@@ -36,6 +36,8 @@ enum adapter_clk_mode {
 	CLOCK_MODE_RCLK
 };
 
+#define DEFAULT_CLOCK_SPEED_KHZ		100U
+
 /**
  * Adapter configuration
  */
@@ -70,6 +72,18 @@ int adapter_init(struct command_context *cmd_ctx)
 	}
 
 	int retval;
+
+	if (adapter_config.clock_mode == CLOCK_MODE_UNSELECTED) {
+		LOG_WARNING("An adapter speed is not selected in the init scripts."
+			" OpenOCD will try to run the adapter at the low speed (%d kHz)",
+			DEFAULT_CLOCK_SPEED_KHZ);
+		LOG_WARNING("To remove this warnings and achieve reasonable communication speed with the target,"
+		    " set \"adapter speed\" or \"jtag_rclk\" in the init scripts.");
+		retval = adapter_config_khz(DEFAULT_CLOCK_SPEED_KHZ);
+		if (retval != ERROR_OK)
+			return ERROR_JTAG_INIT_FAILED;
+	}
+
 	retval = adapter_driver->init();
 	if (retval != ERROR_OK)
 		return retval;
@@ -80,12 +94,6 @@ int adapter_init(struct command_context *cmd_ctx)
 		return ERROR_OK;
 	}
 
-	if (adapter_config.clock_mode == CLOCK_MODE_UNSELECTED) {
-		LOG_ERROR("An adapter speed is not selected in the init script."
-			" Insert a call to \"adapter speed\" or \"jtag_rclk\" to proceed.");
-		return ERROR_JTAG_INIT_FAILED;
-	}
-
 	int requested_khz = adapter_get_speed_khz();
 	int actual_khz = requested_khz;
 	int speed_var = 0;