diff --git a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,9 @@
+arduino-copilot (1.5.7) unstable; urgency=medium
+
+  * Update to copilot-3.7.
+
+ -- Joey Hess <id@joeyh.name>  Wed, 02 Feb 2022 11:07:53 -0400
+
 arduino-copilot (1.5.6) unstable; urgency=medium
 
   * Update to copilot-3.6.
diff --git a/Examples/Blink/stack.yaml b/Examples/Blink/stack.yaml
--- a/Examples/Blink/stack.yaml
+++ b/Examples/Blink/stack.yaml
@@ -3,12 +3,12 @@
 - '../..'
 resolver: lts-18.9
 extra-deps: 
-- copilot-3.6
-- copilot-c99-3.6
-- copilot-core-3.6
-- copilot-language-3.6
-- copilot-libraries-3.6
-- copilot-theorem-3.6
+- copilot-3.7
+- copilot-c99-3.7
+- copilot-core-3.7
+- copilot-language-3.7
+- copilot-libraries-3.7
+- copilot-theorem-3.7
 - ansi-terminal-0.9.1
 - bimap-0.3.3
 - language-c99-0.1.2
diff --git a/Examples/Button/stack.yaml b/Examples/Button/stack.yaml
--- a/Examples/Button/stack.yaml
+++ b/Examples/Button/stack.yaml
@@ -3,12 +3,12 @@
 - '../..'
 resolver: lts-18.9
 extra-deps: 
-- copilot-3.6
-- copilot-c99-3.6
-- copilot-core-3.6
-- copilot-language-3.6
-- copilot-libraries-3.6
-- copilot-theorem-3.6
+- copilot-3.7
+- copilot-c99-3.7
+- copilot-core-3.7
+- copilot-language-3.7
+- copilot-libraries-3.7
+- copilot-theorem-3.7
 - ansi-terminal-0.9.1
 - bimap-0.3.3
 - language-c99-0.1.2
diff --git a/Examples/ButtonHold/stack.yaml b/Examples/ButtonHold/stack.yaml
--- a/Examples/ButtonHold/stack.yaml
+++ b/Examples/ButtonHold/stack.yaml
@@ -3,12 +3,12 @@
 - '../..'
 resolver: lts-18.9
 extra-deps: 
-- copilot-3.6
-- copilot-c99-3.6
-- copilot-core-3.6
-- copilot-language-3.6
-- copilot-libraries-3.6
-- copilot-theorem-3.6
+- copilot-3.7
+- copilot-c99-3.7
+- copilot-core-3.7
+- copilot-language-3.7
+- copilot-libraries-3.7
+- copilot-theorem-3.7
 - ansi-terminal-0.9.1
 - bimap-0.3.3
 - language-c99-0.1.2
diff --git a/Examples/EEPROM/stack.yaml b/Examples/EEPROM/stack.yaml
--- a/Examples/EEPROM/stack.yaml
+++ b/Examples/EEPROM/stack.yaml
@@ -3,12 +3,12 @@
 - '../..'
 resolver: lts-18.9
 extra-deps: 
-- copilot-3.6
-- copilot-c99-3.6
-- copilot-core-3.6
-- copilot-language-3.6
-- copilot-libraries-3.6
-- copilot-theorem-3.6
+- copilot-3.7
+- copilot-c99-3.7
+- copilot-core-3.7
+- copilot-language-3.7
+- copilot-libraries-3.7
+- copilot-theorem-3.7
 - ansi-terminal-0.9.1
 - bimap-0.3.3
 - language-c99-0.1.2
diff --git a/Examples/EEPROMrange/stack.yaml b/Examples/EEPROMrange/stack.yaml
--- a/Examples/EEPROMrange/stack.yaml
+++ b/Examples/EEPROMrange/stack.yaml
@@ -3,12 +3,12 @@
 - '../..'
 resolver: lts-18.9
 extra-deps: 
-- copilot-3.6
-- copilot-c99-3.6
-- copilot-core-3.6
-- copilot-language-3.6
-- copilot-libraries-3.6
-- copilot-theorem-3.6
+- copilot-3.7
+- copilot-c99-3.7
+- copilot-core-3.7
+- copilot-language-3.7
+- copilot-libraries-3.7
+- copilot-theorem-3.7
 - ansi-terminal-0.9.1
 - bimap-0.3.3
 - language-c99-0.1.2
diff --git a/Examples/Random/stack.yaml b/Examples/Random/stack.yaml
--- a/Examples/Random/stack.yaml
+++ b/Examples/Random/stack.yaml
@@ -3,12 +3,12 @@
 - '../..'
 resolver: lts-18.9
 extra-deps: 
-- copilot-3.6
-- copilot-c99-3.6
-- copilot-core-3.6
-- copilot-language-3.6
-- copilot-libraries-3.6
-- copilot-theorem-3.6
+- copilot-3.7
+- copilot-c99-3.7
+- copilot-core-3.7
+- copilot-language-3.7
+- copilot-libraries-3.7
+- copilot-theorem-3.7
 - ansi-terminal-0.9.1
 - bimap-0.3.3
 - language-c99-0.1.2
diff --git a/Examples/SerialPort/stack.yaml b/Examples/SerialPort/stack.yaml
--- a/Examples/SerialPort/stack.yaml
+++ b/Examples/SerialPort/stack.yaml
@@ -3,12 +3,12 @@
 - '../..'
 resolver: lts-18.9
 extra-deps: 
-- copilot-3.6
-- copilot-c99-3.6
-- copilot-core-3.6
-- copilot-language-3.6
-- copilot-libraries-3.6
-- copilot-theorem-3.6
+- copilot-3.7
+- copilot-c99-3.7
+- copilot-core-3.7
+- copilot-language-3.7
+- copilot-libraries-3.7
+- copilot-theorem-3.7
 - ansi-terminal-0.9.1
 - bimap-0.3.3
 - language-c99-0.1.2
diff --git a/Examples/WaterHeater/stack.yaml b/Examples/WaterHeater/stack.yaml
--- a/Examples/WaterHeater/stack.yaml
+++ b/Examples/WaterHeater/stack.yaml
@@ -3,12 +3,12 @@
 - '../..'
 resolver: lts-18.9
 extra-deps: 
-- copilot-3.6
-- copilot-c99-3.6
-- copilot-core-3.6
-- copilot-language-3.6
-- copilot-libraries-3.6
-- copilot-theorem-3.6
+- copilot-3.7
+- copilot-c99-3.7
+- copilot-core-3.7
+- copilot-language-3.7
+- copilot-libraries-3.7
+- copilot-theorem-3.7
 - ansi-terminal-0.9.1
 - bimap-0.3.3
 - language-c99-0.1.2
diff --git a/arduino-copilot.cabal b/arduino-copilot.cabal
--- a/arduino-copilot.cabal
+++ b/arduino-copilot.cabal
@@ -1,5 +1,5 @@
 Name: arduino-copilot
-Version: 1.5.6
+Version: 1.5.7
 Cabal-Version: >= 1.10
 License: BSD3
 Maintainer: Joey Hess <id@joeyh.name>
@@ -114,9 +114,9 @@
     Copilot.Arduino.Main
   Build-Depends:
     base (>= 4.5 && < 5),
-    copilot (== 3.6.*),
-    copilot-c99 (== 3.6.*),
-    copilot-language (== 3.6.*),
+    copilot (== 3.7.*),
+    copilot-c99 (== 3.7.*),
+    copilot-language (== 3.7.*),
     filepath,
     directory,
     mtl,
diff --git a/stack.yaml b/stack.yaml
--- a/stack.yaml
+++ b/stack.yaml
@@ -2,12 +2,12 @@
 - '.'
 resolver: lts-18.9
 extra-deps:
-- copilot-3.6
-- copilot-c99-3.6
-- copilot-core-3.6
-- copilot-language-3.6
-- copilot-libraries-3.6
-- copilot-theorem-3.6
+- copilot-3.7
+- copilot-c99-3.7
+- copilot-core-3.7
+- copilot-language-3.7
+- copilot-libraries-3.7
+- copilot-theorem-3.7
 - ansi-terminal-0.9.1
 - bimap-0.3.3
 - language-c99-0.1.2