diff --git a/src/SUMMARY.md b/src/SUMMARY.md
index d07facc38..adc397fd8 100644
--- a/src/SUMMARY.md
+++ b/src/SUMMARY.md
@@ -8,7 +8,7 @@
 
 # Building and debugging `rustc`
 
-- [How to Build and Run the Compiler](./building/how-to-build-and-run.md)
+- [How to build and run the compiler](./building/how-to-build-and-run.md)
     - [Prerequisites](./building/prerequisites.md)
     - [Suggested Workflows](./building/suggested.md)
     - [Distribution artifacts](./building/build-install-distribution-artifacts.md)
@@ -25,7 +25,7 @@
         - [Test headers](./tests/headers.md)
     - [Performance testing](./tests/perf.md)
     - [Crater](./tests/crater.md)
-- [Debugging the Compiler](./compiler-debugging.md)
+- [Debugging the compiler](./compiler-debugging.md)
     - [Using the tracing/logging instrumentation](./tracing.md)
 - [Profiling the compiler](./profiling.md)
     - [with the linux perf tool](./profiling/with_perf.md)
@@ -57,7 +57,7 @@
 # High-level Compiler Architecture
 
 - [Prologue](./part-2-intro.md)
-- [Overview of the Compiler](./overview.md)
+- [Overview of the compiler](./overview.md)
 - [The compiler source code](./compiler-src.md)
 - [Bootstrapping](./building/bootstrapping.md)
 - [Queries: demand-driven compilation](./query.md)
@@ -95,7 +95,7 @@
     - [MIR construction](./mir/construction.md)
     - [MIR visitor and traversal](./mir/visitor.md)
     - [MIR passes: getting the MIR for a function](./mir/passes.md)
-- [Identifiers in the Compiler](./identifiers.md)
+- [Identifiers in the compiler](./identifiers.md)
 - [Closure expansion](./closure.md)
 - [Inline assembly](./asm.md)
 
@@ -168,7 +168,7 @@
 - [Profile-guided Optimization](./profile-guided-optimization.md)
 - [LLVM Source-Based Code Coverage](./llvm-coverage-instrumentation.md)
 - [Sanitizers Support](./sanitizers.md)
-- [Debugging Support in the Rust Compiler](./debugging-support-in-rustc.md)
+- [Debugging support in the Rust compiler](./debugging-support-in-rustc.md)
 
 ---
 
diff --git a/src/building/bootstrapping.md b/src/building/bootstrapping.md
index 5f49f2b19..fe34cb500 100644
--- a/src/building/bootstrapping.md
+++ b/src/building/bootstrapping.md
@@ -1,4 +1,4 @@
-# Bootstrapping the Compiler
+# Bootstrapping the compiler
 
 <!-- toc -->
 
@@ -90,7 +90,7 @@ because one must first build the new compiler with an older compiler
 and then use that to build the new compiler with itself.
 For development, you usually only want the `stage1` compiler,
 which you can build with `./x.py build library`.
-See [Building the Compiler](./how-to-build-and-run.html#building-the-compiler).
+See [Building the compiler](./how-to-build-and-run.html#building-the-compiler).
 
 ### Stage 3
 
diff --git a/src/building/how-to-build-and-run.md b/src/building/how-to-build-and-run.md
index fdfc1786e..eb9bbff9c 100644
--- a/src/building/how-to-build-and-run.md
+++ b/src/building/how-to-build-and-run.md
@@ -1,4 +1,4 @@
-# How to Build and Run the Compiler
+# How to build and run the compiler
 
 The compiler is built using a tool called `x.py`. You will need to
 have Python installed to run it.
@@ -52,7 +52,7 @@ If you have already built `rustc` and you change settings related to LLVM, then
 execute `rm -rf build` for subsequent configuration changes to take effect. Note that `./x.py
 clean` will not cause a rebuild of LLVM.
 
-## Building the Compiler
+## Building the compiler
 
 Note that building will require a relatively large amount of storage space.
 You may want to have upwards of 10 or 15 gigabytes available to build the compiler.
diff --git a/src/getting-started.md b/src/getting-started.md
index b9e96844e..bc294d1b3 100644
--- a/src/getting-started.md
+++ b/src/getting-started.md
@@ -81,7 +81,7 @@ normally used for: building, testing, creating releases, formatting, etc.
 
 [bootstrapping]: ./building/bootstrapping.md
 
-### Configuring the Compiler
+### Configuring the compiler
 
 In the top level of the repo:
 
diff --git a/src/identifiers.md b/src/identifiers.md
index 18a3efefc..1b60b3b0b 100644
--- a/src/identifiers.md
+++ b/src/identifiers.md
@@ -1,4 +1,4 @@
-# Identifiers in the Compiler
+# Identifiers in the compiler
 
 If you have read the few previous chapters, you now know that `rustc` uses
 many different intermediate representations to perform different kinds of analyses.
diff --git a/src/overview.md b/src/overview.md
index ca37f94b2..de06c742b 100644
--- a/src/overview.md
+++ b/src/overview.md
@@ -1,4 +1,4 @@
-# Overview of the Compiler
+# Overview of the compiler
 
 <!-- toc -->