diff --git a/libtest.png b/libtest.png
index 3b393be..c441cca 100644
Binary files a/libtest.png and b/libtest.png differ
diff --git a/readme.md b/readme.md
index 5b274b3..01b8a60 100644
--- a/readme.md
+++ b/readme.md
@@ -2837,7 +2837,8 @@ PCBs and perfboard with optional components. The shape can be a rectangle with o
 |   1 | `pcb(DuetE)` |  Duet 2 Ethernet electronics |
 |   1 | `pcb(Duex2)` |  Duex2 expansion board - not shown |
 |   1 | `pcb(Duex5)` |  Duex5 expansion board |
-|   1 | `pcb(ESP-01)` |  ESP-01 |
+|   1 | `pcb(ESP_01)` |  ESP-01 |
+|   1 | `pcb(ESP_01M)` |  ESP-01M WiFi module (ESP8285) |
 |   1 | `pcb(ESP_12F)` |  ESP-12F ESP8266 WiFi module |
 |   1 | `pcb(ESP_201)` |  ESP-201 ESP8266 WiFi module |
 |   1 | `pcb(ESP32_DOIT_V1)` |  ESP32 DOIT DEV KIT V1 |
diff --git a/tests/png/pcbs.png b/tests/png/pcbs.png
index dfb1a58..4506e21 100644
Binary files a/tests/png/pcbs.png and b/tests/png/pcbs.png differ
diff --git a/vitamins/pcbs.scad b/vitamins/pcbs.scad
index ec69a95..f55c648 100644
--- a/vitamins/pcbs.scad
+++ b/vitamins/pcbs.scad
@@ -837,7 +837,7 @@ RAMPSEndstop = ["RAMPSEndstop", "RAMPS Endstop Switch",
     []];
 
 ESP_01 = [
-    "ESP-01", "ESP-01",
+    "ESP_01", "ESP-01",
     24.8, 14.6, 1, // size
     0, // corner radius
     0, // mounting hole diameter
@@ -868,7 +868,7 @@ ESP_01 = [
 // by Karl McMurdo (XrXca)
 //================================================
 ESP_01M = [
-    "ESP-01M", "ESP-01M WiFi module (ESP8285)",
+    "ESP_01M", "ESP-01M WiFi module (ESP8285)",
     18, 18, 0.8, // size
     0, // corner radius
     0, // mounting hole diameter