diff --git a/cortex-m/src/peripheral/mod.rs b/cortex-m/src/peripheral/mod.rs
index d65707c1..5c0d5d1f 100644
--- a/cortex-m/src/peripheral/mod.rs
+++ b/cortex-m/src/peripheral/mod.rs
@@ -163,6 +163,8 @@ impl Peripherals {
             if unsafe { TAKEN } {
                 None
             } else {
+                unsafe { TAKEN = true }
+
                 Some(unsafe { Peripherals::steal() })
             }
         })
@@ -170,58 +172,54 @@ impl Peripherals {
 
     /// Unchecked version of `Peripherals::take`
     #[inline]
-    pub unsafe fn steal() -> Self {
-        unsafe {
-            TAKEN = true;
-
-            Peripherals {
-                #[cfg(feature = "cm7")]
-                AC: AC {
-                    _marker: PhantomData,
-                },
-                CBP: CBP {
-                    _marker: PhantomData,
-                },
-                CPUID: CPUID {
-                    _marker: PhantomData,
-                },
-                DCB: DCB {
-                    _marker: PhantomData,
-                },
-                DWT: DWT {
-                    _marker: PhantomData,
-                },
-                FPB: FPB {
-                    _marker: PhantomData,
-                },
-                FPU: FPU {
-                    _marker: PhantomData,
-                },
-                ICB: ICB {
-                    _marker: PhantomData,
-                },
-                ITM: ITM {
-                    _marker: PhantomData,
-                },
-                MPU: MPU {
-                    _marker: PhantomData,
-                },
-                NVIC: NVIC {
-                    _marker: PhantomData,
-                },
-                SAU: SAU {
-                    _marker: PhantomData,
-                },
-                SCB: SCB {
-                    _marker: PhantomData,
-                },
-                SYST: SYST {
-                    _marker: PhantomData,
-                },
-                TPIU: TPIU {
-                    _marker: PhantomData,
-                },
-            }
+    pub const unsafe fn steal() -> Self {
+        Peripherals {
+            #[cfg(feature = "cm7")]
+            AC: AC {
+                _marker: PhantomData,
+            },
+            CBP: CBP {
+                _marker: PhantomData,
+            },
+            CPUID: CPUID {
+                _marker: PhantomData,
+            },
+            DCB: DCB {
+                _marker: PhantomData,
+            },
+            DWT: DWT {
+                _marker: PhantomData,
+            },
+            FPB: FPB {
+                _marker: PhantomData,
+            },
+            FPU: FPU {
+                _marker: PhantomData,
+            },
+            ICB: ICB {
+                _marker: PhantomData,
+            },
+            ITM: ITM {
+                _marker: PhantomData,
+            },
+            MPU: MPU {
+                _marker: PhantomData,
+            },
+            NVIC: NVIC {
+                _marker: PhantomData,
+            },
+            SAU: SAU {
+                _marker: PhantomData,
+            },
+            SCB: SCB {
+                _marker: PhantomData,
+            },
+            SYST: SYST {
+                _marker: PhantomData,
+            },
+            TPIU: TPIU {
+                _marker: PhantomData,
+            },
         }
     }
 }
diff --git a/xtask/tests/ci.rs b/xtask/tests/ci.rs
index 410e59b9..947f0a59 100644
--- a/xtask/tests/ci.rs
+++ b/xtask/tests/ci.rs
@@ -50,7 +50,7 @@ static PACKAGE_FEATURES: &[(&str, &[&str], &[&str])] = &[
     ("panic-itm", NON_BASE_TARGETS, &[]),
 ];
 
-fn check_crates_build(is_nightly: bool, is_msrv: bool) {
+fn check_crates_build(is_nightly: bool, _is_msrv: bool) {
     // Build all crates for each supported target.
     for (package, targets, all_features) in PACKAGE_FEATURES {
         for target in *targets {