diff --git a/.travis.yml b/.travis.yml
index 325f3eb..76182e5 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -7,6 +7,7 @@ os:
 language: d
 
 d:
+  - dmd-2.078.0
   - dmd-2.077.1
   - dmd-2.076.1
 
@@ -21,7 +22,7 @@ addons:
       - gcc-multilib
 
 before_script:
-  - if [ "$PS1" = '(dmd-2.077.1)' ]; then
+  - if [ "$PS1" = '(dmd-2.078.0)' ]; then
       export UNITTEST="unittest-cov";
     fi
 
diff --git a/README.md b/README.md
index 281f757..da4809c 100644
--- a/README.md
+++ b/README.md
@@ -149,7 +149,8 @@ There are more containers in the `tanya.container` package.
 
 | DMD     | GCC            |
 |:-------:|:--------------:|
-| 2.077.0 | *gdc-5* branch |
+| 2.078.0 | *gdc-5* branch |
+| 2.077.1 |                |
 | 2.076.1 |                |
 
 ### Current status
@@ -163,9 +164,7 @@ Following modules are under development:
 
 ### Release management
 
-3-week release cycle.
-
-Deprecated features are removed after one release (in approximately 6 weeks after deprecating).
+Deprecated features are removed after one release that includes these deprecations.
 
 ## Further characteristics
 
diff --git a/appveyor.yml b/appveyor.yml
index 57088ba..1206e78 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -3,6 +3,12 @@ os: Visual Studio 2015
 
 environment:
   matrix:
+    - DC: dmd
+      DVersion: 2.078.0
+      arch: x64
+    - DC: dmd
+      DVersion: 2.078.0
+      arch: x86
     - DC: dmd
       DVersion: 2.077.1
       arch: x64
diff --git a/source/tanya/container/string.d b/source/tanya/container/string.d
index 73aab41..1b95cfd 100644
--- a/source/tanya/container/string.d
+++ b/source/tanya/container/string.d
@@ -264,7 +264,8 @@ if (is(Unqual!E == char))
     body
     {
         dchar chr;
-        ubyte units, mask;
+        ubyte units;
+        int mask;
         const(char)* it = this.begin;
 
         if (*it & 0x80)
diff --git a/source/tanya/math/mp.d b/source/tanya/math/mp.d
index a045b25..f062c47 100644
--- a/source/tanya/math/mp.d
+++ b/source/tanya/math/mp.d
@@ -393,7 +393,9 @@ struct Integer
     T opCast(T)() const
     if (isIntegral!T && isSigned!T)
     {
-        return this.sign ? -(cast(Unsigned!T) this) : cast(Unsigned!T) this;
+        return this.sign
+            ? cast(T) -(cast(Promoted!(Unsigned!T)) (cast(Unsigned!T) this))
+            : cast(Unsigned!T) this;
     }
 
     ///
@@ -1072,7 +1074,7 @@ struct Integer
         assert(h1 == 79);
 
         h2 = ~h1;
-        assert(h2 == ~cast(ubyte) 79);
+        assert(h2 == cast(ubyte) ~79);
     }
 
     /// ditto