diff --git a/bin/Cargo.toml b/bin/Cargo.toml
index 484d010..2ead6e0 100644
--- a/bin/Cargo.toml
+++ b/bin/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "data-encoding-bin"
-version = "0.3.3"
+version = "0.3.4-git"
 authors = ["Julien Cretin <git@ia0.eu>"]
 license = "MIT"
 edition = "2021"
@@ -16,5 +16,5 @@ name = "data-encoding"
 path = "src/main.rs"
 
 [dependencies]
-data-encoding = { version = "2.5.0", path = "../lib" }
+data-encoding = { version = "2.6.0-git", path = "../lib" }
 getopts = "0.2"
diff --git a/lib/CHANGELOG.md b/lib/CHANGELOG.md
index 6b2b3a9..f668d72 100644
--- a/lib/CHANGELOG.md
+++ b/lib/CHANGELOG.md
@@ -1,5 +1,11 @@
 # Changelog
 
+## 2.6.0-git
+
+### Minor
+
+- Add `BASE64_MIME_PERMISSIVE` constant to ignore trailing bits (fixes #102)
+
 ## 2.5.0
 
 ### Minor
diff --git a/lib/Cargo.toml b/lib/Cargo.toml
index 19ca78b..531c7c7 100644
--- a/lib/Cargo.toml
+++ b/lib/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "data-encoding"
-version = "2.5.0"
+version = "2.6.0-git"
 authors = ["Julien Cretin <git@ia0.eu>"]
 license = "MIT"
 edition = "2018"
diff --git a/lib/README.md b/lib/README.md
index 41e5d86..f2d892e 100644
--- a/lib/README.md
+++ b/lib/README.md
@@ -3,23 +3,24 @@
 
 This library provides the following common encodings:
 
-| Name                  | Description                                       |
-| ---                   | ---                                               |
-| `HEXLOWER`            | lowercase hexadecimal                             |
-| `HEXLOWER_PERMISSIVE` | lowercase hexadecimal (case-insensitive decoding) |
-| `HEXUPPER`            | uppercase hexadecimal                             |
-| `HEXUPPER_PERMISSIVE` | uppercase hexadecimal (case-insensitive decoding) |
-| `BASE32`              | RFC4648 base32                                    |
-| `BASE32_NOPAD`        | RFC4648 base32 (no padding)                       |
-| `BASE32_DNSSEC`       | RFC5155 base32                                    |
-| `BASE32_DNSCURVE`     | DNSCurve base32                                   |
-| `BASE32HEX`           | RFC4648 base32hex                                 |
-| `BASE32HEX_NOPAD`     | RFC4648 base32hex (no padding)                    |
-| `BASE64`              | RFC4648 base64                                    |
-| `BASE64_NOPAD`        | RFC4648 base64 (no padding)                       |
-| `BASE64_MIME`         | RFC2045-like base64                               |
-| `BASE64URL`           | RFC4648 base64url                                 |
-| `BASE64URL_NOPAD`     | RFC4648 base64url (no padding)                    |
+| Name                     | Description                                       |
+|--------------------------|---------------------------------------------------|
+| `HEXLOWER`               | lowercase hexadecimal                             |
+| `HEXLOWER_PERMISSIVE`    | lowercase hexadecimal (case-insensitive decoding) |
+| `HEXUPPER`               | uppercase hexadecimal                             |
+| `HEXUPPER_PERMISSIVE`    | uppercase hexadecimal (case-insensitive decoding) |
+| `BASE32`                 | RFC4648 base32                                    |
+| `BASE32_NOPAD`           | RFC4648 base32 (no padding)                       |
+| `BASE32_DNSSEC`          | RFC5155 base32                                    |
+| `BASE32_DNSCURVE`        | DNSCurve base32                                   |
+| `BASE32HEX`              | RFC4648 base32hex                                 |
+| `BASE32HEX_NOPAD`        | RFC4648 base32hex (no padding)                    |
+| `BASE64`                 | RFC4648 base64                                    |
+| `BASE64_NOPAD`           | RFC4648 base64 (no padding)                       |
+| `BASE64_MIME`            | RFC2045-like base64                               |
+| `BASE64_MIME_PERMISSIVE` | RFC2045-like base64 (ignoring trailing bits)      |
+| `BASE64URL`              | RFC4648 base64url                                 |
+| `BASE64URL_NOPAD`        | RFC4648 base64url (no padding)                    |
 
 It also provides the possibility to define custom little-endian ASCII
 base-conversion encodings for bases of size 2, 4, 8, 16, 32, and 64 (for which
diff --git a/lib/macro/Cargo.toml b/lib/macro/Cargo.toml
index 87f92d0..a085616 100644
--- a/lib/macro/Cargo.toml
+++ b/lib/macro/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "data-encoding-macro"
-version = "0.1.14"
+version = "0.1.15-git"
 authors = ["Julien Cretin <cretin@google.com>"]
 license = "MIT"
 edition = "2018"
@@ -14,5 +14,5 @@ description = "Macros for data-encoding"
 include = ["Cargo.toml", "LICENSE", "README.md", "src/lib.rs"]
 
 [dependencies]
-data-encoding = { version = "2.5.0", path = "..", default-features = false }
-data-encoding-macro-internal = { version = "0.1.12", path = "internal" }
+data-encoding = { version = "2.6.0-git", path = "..", default-features = false }
+data-encoding-macro-internal = { version = "0.1.13-git", path = "internal" }
diff --git a/lib/macro/internal/Cargo.toml b/lib/macro/internal/Cargo.toml
index 7246d7e..5594425 100644
--- a/lib/macro/internal/Cargo.toml
+++ b/lib/macro/internal/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "data-encoding-macro-internal"
-version = "0.1.12"
+version = "0.1.13-git"
 authors = ["Julien Cretin <cretin@google.com>"]
 license = "MIT"
 edition = "2018"
@@ -14,7 +14,7 @@ include = ["Cargo.toml", "LICENSE", "README.md", "src/lib.rs"]
 proc-macro = true
 
 [dependencies.data-encoding]
-version = "2.5.0"
+version = "2.6.0-git"
 path = "../.."
 default-features = false
 features = ["alloc"]
diff --git a/lib/macro/src/lib.rs b/lib/macro/src/lib.rs
index a0d8087..a9fc654 100644
--- a/lib/macro/src/lib.rs
+++ b/lib/macro/src/lib.rs
@@ -246,6 +246,14 @@ make! {
     wrap_width: 76,
     wrap_separator: "\r\n",
 }
+make! {
+    base64_mime_permissive base64_mime_permissive_array = BASE64_MIME_PERMISSIVE;
+    symbols: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/",
+    padding: '=',
+    wrap_width: 76,
+    wrap_separator: "\r\n",
+    check_trailing_bits: false,
+}
 make! {
     base64url base64url_array = BASE64URL;
     symbols: "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_",
diff --git a/lib/src/lib.rs b/lib/src/lib.rs
index 22743ee..ed8b194 100644
--- a/lib/src/lib.rs
+++ b/lib/src/lib.rs
@@ -2387,7 +2387,7 @@ const BASE64_NOPAD_IMPL: &[u8] = &[
 /// This encoding is a static version of:
 ///
 /// ```rust
-/// # use data_encoding::{Specification, Wrap, BASE64_MIME};
+/// # use data_encoding::{Specification, BASE64_MIME};
 /// let mut spec = Specification::new();
 /// spec.symbols.push_str("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/");
 /// spec.padding = Some('=');
@@ -2429,6 +2429,54 @@ const BASE64_MIME_IMPL: &[u8] = &[
     128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 61, 30, 76, 13, 10,
 ];
 
+/// MIME base64 encoding without trailing bits check
+///
+/// This encoding is a static version of:
+///
+/// ```rust
+/// # use data_encoding::{Specification, BASE64_MIME_PERMISSIVE};
+/// let mut spec = Specification::new();
+/// spec.symbols.push_str("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/");
+/// spec.padding = Some('=');
+/// spec.wrap.width = 76;
+/// spec.wrap.separator.push_str("\r\n");
+/// spec.check_trailing_bits = false;
+/// assert_eq!(BASE64_MIME_PERMISSIVE, spec.encoding().unwrap());
+/// ```
+///
+/// It does not exactly conform to [RFC2045] because it does not print the header
+/// and does not ignore all characters.
+///
+/// [RFC2045]: https://tools.ietf.org/html/rfc2045
+pub const BASE64_MIME_PERMISSIVE: Encoding = Encoding::internal_new(BASE64_MIME_PERMISSIVE_IMPL);
+const BASE64_MIME_PERMISSIVE_IMPL: &[u8] = &[
+    65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88,
+    89, 90, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114,
+    115, 116, 117, 118, 119, 120, 121, 122, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 43, 47, 65, 66,
+    67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90,
+    97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115,
+    116, 117, 118, 119, 120, 121, 122, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 43, 47, 65, 66, 67,
+    68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 97,
+    98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116,
+    117, 118, 119, 120, 121, 122, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 43, 47, 65, 66, 67, 68,
+    69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 97, 98,
+    99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117,
+    118, 119, 120, 121, 122, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 43, 47, 128, 128, 128, 128,
+    128, 128, 128, 128, 128, 128, 129, 128, 128, 129, 128, 128, 128, 128, 128, 128, 128, 128, 128,
+    128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
+    128, 62, 128, 128, 128, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 128, 128, 128, 130, 128,
+    128, 128, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23,
+    24, 25, 128, 128, 128, 128, 128, 128, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39,
+    40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 128, 128, 128, 128, 128, 128, 128, 128, 128,
+    128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
+    128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
+    128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
+    128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
+    128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
+    128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
+    128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 61, 14, 76, 13, 10,
+];
+
 /// Padded base64url encoding
 ///
 /// This encoding is a static version of:
diff --git a/lib/tests/lib.rs b/lib/tests/lib.rs
index 91f86ba..b3a2ada 100644
--- a/lib/tests/lib.rs
+++ b/lib/tests/lib.rs
@@ -412,6 +412,7 @@ fn round_trip() {
     test(data_encoding::BASE64);
     test(data_encoding::BASE64_NOPAD);
     test(data_encoding::BASE64_MIME);
+    test(data_encoding::BASE64_MIME_PERMISSIVE);
     test(data_encoding::BASE64URL);
     test(data_encoding::BASE64URL_NOPAD);
 }
diff --git a/www/Cargo.toml b/www/Cargo.toml
index 708500d..bca5756 100644
--- a/www/Cargo.toml
+++ b/www/Cargo.toml
@@ -12,7 +12,7 @@ publish = false
 crate-type = ["cdylib"]
 
 [dependencies]
-data-encoding = "2"
+data-encoding = { path = "../lib" }
 lazy_static = "1"
 wasm-bindgen = "0.2"
 
diff --git a/www/src/lib.rs b/www/src/lib.rs
index 73345f2..0328ca7 100644
--- a/www/src/lib.rs
+++ b/www/src/lib.rs
@@ -63,6 +63,7 @@ lazy_static! {
         add!(BASE64URL);
         add!(BASE64URL_NOPAD);
         add!(BASE64_MIME);
+        add!(BASE64_MIME_PERMISSIVE);
         add!(BASE64_NOPAD);
         add!(HEXLOWER);
         add!(HEXLOWER_PERMISSIVE);