diff --git a/.github/workflows/rust.yml b/.github/workflows/rust.yml
index 6ba61f3d0..ae52b1278 100644
--- a/.github/workflows/rust.yml
+++ b/.github/workflows/rust.yml
@@ -250,11 +250,11 @@ jobs:
 
       - uses: actions-rs/toolchain@v1
         with:
-          toolchain: "1.67.0"
+          toolchain: "1.74.0"
           override: true
 
       - name: check if README matches MSRV defined here
-        run: grep '1.67.0' src/core/README.md
+        run: grep '1.74.0' src/core/README.md
 
       - name: Check if it builds properly
         uses: actions-rs/cargo@v1
diff --git a/Cargo.lock b/Cargo.lock
index e5441852d..6245360df 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1840,9 +1840,9 @@ checksum = "3550f4e9685620ac18a50ed434eb3aec30db8ba93b0287467bca5826ea25baf1"
 
 [[package]]
 name = "toml_edit"
-version = "0.21.0"
+version = "0.21.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d34d383cd00a163b4a5b85053df514d45bc330f6de7737edfe0a93311d1eaa03"
+checksum = "6a8534fd7f78b5405e860340ad6575217ce99f38d4d5c8f2442cb5ecb50090e1"
 dependencies = [
  "indexmap",
  "toml_datetime",
diff --git a/src/core/Cargo.toml b/src/core/Cargo.toml
index 8d367b991..e1c77779e 100644
--- a/src/core/Cargo.toml
+++ b/src/core/Cargo.toml
@@ -11,7 +11,7 @@ edition = "2021"
 readme = "README.md"
 autoexamples = false
 autobins = false
-rust-version = "1.67.0"
+rust-version = "1.74.0"
 
 [lib]
 name = "sourmash"
@@ -48,8 +48,6 @@ num-iter = "0.1.44"
 once_cell = "1.18.0"
 ouroboros = "0.18.3"
 primal-check = "0.3.1"
-rc-zip = { version = "4.0.0", default-features = false }
-rc-zip-sync = "4.0.0"
 rkyv = { version = "0.7.44", optional = true }
 roaring = "0.10.2"
 rayon = { version = "1.8.1", optional = true }
@@ -106,3 +104,5 @@ wasm-bindgen-test = "0.3.41"
 ### These crates don't compile on wasm
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 rocksdb = { version = "0.21.0", optional = true }
+rc-zip = { version = "4.0.0", default-features = false }
+rc-zip-sync = "4.0.0"
diff --git a/src/core/README.md b/src/core/README.md
index 3f4cc9f60..a17319868 100644
--- a/src/core/README.md
+++ b/src/core/README.md
@@ -38,4 +38,4 @@ Development happens on github at
 
 ## Minimum supported Rust version
 
-Currently the minimum supported Rust version is 1.67.0.
+Currently the minimum supported Rust version is 1.74.0.
diff --git a/src/core/src/errors.rs b/src/core/src/errors.rs
index 46dedfc1e..70e12b6f0 100644
--- a/src/core/src/errors.rs
+++ b/src/core/src/errors.rs
@@ -67,13 +67,14 @@ pub enum SourmashError {
     #[error(transparent)]
     CsvError(#[from] csv::Error),
 
-    #[error(transparent)]
-    ZipError(#[from] rc_zip::error::Error),
-
     #[cfg(not(all(target_arch = "wasm32", target_os = "unknown")))]
     #[error(transparent)]
     Panic(#[from] crate::ffi::utils::Panic),
 
+    #[cfg(not(target_arch = "wasm32"))]
+    #[error(transparent)]
+    ZipError(#[from] rc_zip::error::Error),
+
     #[cfg(not(target_arch = "wasm32"))]
     #[cfg(feature = "branchwater")]
     #[error(transparent)]