diff --git a/artiq/firmware/Cargo.lock b/artiq/firmware/Cargo.lock
index b2413039e..0d9aedad3 100644
--- a/artiq/firmware/Cargo.lock
+++ b/artiq/firmware/Cargo.lock
@@ -176,8 +176,8 @@ dependencies = [
 
 [[package]]
 name = "log_buffer"
-version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
+version = "1.2.0"
+source = "git+https://github.com/whitequark/rust-log_buffer?rev=rust-1.25#ff84e565d9954d5864d60aec12b9e1381505d72a"
 
 [[package]]
 name = "logger_artiq"
@@ -185,7 +185,7 @@ version = "0.0.0"
 dependencies = [
  "board 0.0.0",
  "log 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "log_buffer 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "log_buffer 1.2.0 (git+https://github.com/whitequark/rust-log_buffer?rev=rust-1.25)",
 ]
 
 [[package]]
@@ -304,7 +304,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum libc 0.2.40 (registry+https://github.com/rust-lang/crates.io-index)" = "6fd41f331ac7c5b8ac259b8bf82c75c0fb2e469bbf37d2becbba9a6a2221965b"
 "checksum log 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)" = "e19e8d5c34a3e0e2223db8e060f9e8264aeeb5c5fc64a4ee9965c062211c024b"
 "checksum log 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "89f010e843f2b1a31dbd316b3b8d443758bc634bed37aabade59c686d644e0a2"
-"checksum log_buffer 1.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ec57723b84bbe7bdf76aa93169c9b59e67473317c6de3a83cb2a0f8ccb2aa493"
+"checksum log_buffer 1.2.0 (git+https://github.com/whitequark/rust-log_buffer?rev=rust-1.25)" = "<none>"
 "checksum managed 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "43e2737ecabe4ae36a68061398bf27d2bfd0763f4c3c837a398478459494c4b7"
 "checksum managed 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)" = "5a31885241e61ba264d780d2e6686e7e59561c947b4581470364eb3e10102d86"
 "checksum same-file 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "d931a44fdaa43b8637009e7632a02adc4f2b2e0733c08caa4cf00e8da4a117a7"
diff --git a/artiq/firmware/liblogger_artiq/Cargo.toml b/artiq/firmware/liblogger_artiq/Cargo.toml
index 2cf792723..822cae637 100644
--- a/artiq/firmware/liblogger_artiq/Cargo.toml
+++ b/artiq/firmware/liblogger_artiq/Cargo.toml
@@ -9,5 +9,5 @@ path = "lib.rs"
 
 [dependencies]
 log = { version = "0.4", default-features = false }
-log_buffer = { version = "1.0" }
+log_buffer = { version = "1.2", git = "https://github.com/whitequark/rust-log_buffer", rev = "rust-1.25" }
 board = { path = "../libboard" }
diff --git a/artiq/firmware/liblogger_artiq/lib.rs b/artiq/firmware/liblogger_artiq/lib.rs
index 8ccfdc6fb..fd6228978 100644
--- a/artiq/firmware/liblogger_artiq/lib.rs
+++ b/artiq/firmware/liblogger_artiq/lib.rs
@@ -23,8 +23,8 @@ impl<'a> LogBufferRef<'a> {
         LogBufferRef { buffer, old_log_level }
     }
 
-    pub fn is_empty(&mut self) -> bool {
-        self.buffer.extract().len() == 0
+    pub fn is_empty(&self) -> bool {
+        self.buffer.is_empty()
     }
 
     pub fn clear(&mut self) {