diff --git a/src/structs/dmat.rs b/src/structs/dmat.rs
index 93a49071..ab3049f0 100644
--- a/src/structs/dmat.rs
+++ b/src/structs/dmat.rs
@@ -618,13 +618,13 @@ impl<N: ApproxEq<N>> ApproxEq<N> for DMat<N> {
 
     #[inline]
     fn approx_eq_eps(&self, other: &DMat<N>, epsilon: &N) -> bool {
-        let zip = self.mij.iter().zip(other.mij.iter());
+        let mut zip = self.mij.iter().zip(other.mij.iter());
         zip.all(|(a, b)| ApproxEq::approx_eq_eps(a, b, epsilon))
     }
 
     #[inline]
     fn approx_eq_ulps(&self, other: &DMat<N>, ulps: u32) -> bool {
-        let zip = self.mij.iter().zip(other.mij.iter());
+        let mut zip = self.mij.iter().zip(other.mij.iter());
         zip.all(|(a, b)| ApproxEq::approx_eq_ulps(a, b, ulps))
     }
 }
diff --git a/src/structs/dvec_macros.rs b/src/structs/dvec_macros.rs
index f108f090..2624d7b8 100644
--- a/src/structs/dvec_macros.rs
+++ b/src/structs/dvec_macros.rs
@@ -319,13 +319,13 @@ macro_rules! dvec_impl(
 
             #[inline]
             fn approx_eq_eps(&self, other: &$dvec<N>, epsilon: &N) -> bool {
-                let zip = self.as_slice().iter().zip(other.as_slice().iter());
+                let mut zip = self.as_slice().iter().zip(other.as_slice().iter());
                 zip.all(|(a, b)| ApproxEq::approx_eq_eps(a, b, epsilon))
             }
 
             #[inline]
             fn approx_eq_ulps(&self, other: &$dvec<N>, ulps: u32) -> bool {
-                let zip = self.as_slice().iter().zip(other.as_slice().iter());
+                let mut zip = self.as_slice().iter().zip(other.as_slice().iter());
                 zip.all(|(a, b)| ApproxEq::approx_eq_ulps(a, b, ulps))
             }
         }
diff --git a/src/structs/mat_macros.rs b/src/structs/mat_macros.rs
index 5f5bcac1..064ce573 100644
--- a/src/structs/mat_macros.rs
+++ b/src/structs/mat_macros.rs
@@ -646,13 +646,13 @@ macro_rules! approx_eq_impl(
 
         #[inline]
         fn approx_eq_eps(&self, other: &$t<N>, epsilon: &N) -> bool {
-            let zip = self.iter().zip(other.iter());
+            let mut zip = self.iter().zip(other.iter());
             zip.all(|(a, b)| ApproxEq::approx_eq_eps(a, b, epsilon))
         }
 
         #[inline]
         fn approx_eq_ulps(&self, other: &$t<N>, ulps: u32) -> bool {
-            let zip = self.iter().zip(other.iter());
+            let mut zip = self.iter().zip(other.iter());
             zip.all(|(a, b)| ApproxEq::approx_eq_ulps(a, b, ulps))
         }
     }